nrf51822 advertising timeout sleep RAM retention

[mm81]

Hello I would like to know when nrf51822 (SDK v12.3 with SD S130 ) advertising timeout and system goes to sleep , how could I retain the ram data so the MCU could work properly when it is woke up by other event? Thanks.

[ovrebekk]

Hi

When using the SoftDevice you should use the sd_power_ramon_set() function to access the RAMON register.

To enable RAM retention both in system ON and system OFF make sure to set both the OFFRAM0/1 fields and the ONRAM0/1 fields.

Best regards
Torbjørn Øvrebekk

[mm81]

Thanks Torbjørn. Turns out I discovered my problem is the device got RESET when the advertisement got timeout.

I suppose this is because I have some ADC operation going on and the timer and ppi wakes up the mcu from deep sleep.

I have modified ble_advertising.c to change the action of advertising time out from system off to WFE and the problem is solved.

[ovrebekk]

Hi

Do you mean you changed the advertising event handler, or the ble_advertising.c file itself?
Changing the SDK libraries and drivers is not recommended if you can avoid it.

Also, when using the SoftDevice you should use sd_app_evt_wait(), rather than calling __WFE() directly.

Best regards

[mm81]

Thank. I am modifing the ble_advertising.c itself.

Understood, I am new to NRF51 development.

Could you advise where should I modify on application level if i do not want the device go to deep sleep after advertising timeout?

[mm81]

Or you mean i should create a customized version of ble_advertising_on_ble_evt() and call it instead?

[mm81]

Ok, understand thanks!